Question and Answers Forum

AllQuestion and Answers: Page 1854

Question Number 17205 Answers: 1 Comments: 0

lim_(n→∞) Σ_(r=1) ^(n−1) (1/n)(√((n+r)/(n−r)))

$$\underset{\mathrm{n}\rightarrow\infty} {\mathrm{lim}}\:\:\underset{\mathrm{r}=\mathrm{1}} {\overset{\mathrm{n}−\mathrm{1}} {\sum}}\frac{\mathrm{1}}{\mathrm{n}}\sqrt{\frac{\mathrm{n}+\mathrm{r}}{\mathrm{n}−\mathrm{r}}} \\ $$

Question Number 17204 Answers: 2 Comments: 0

∫_0 ^( (Π/2)) sinθ cosθ(a^2 sin^2 θ+b^2 cos^2 θ)^(1/2) dθ

$$\int_{\mathrm{0}} ^{\:\frac{\Pi}{\mathrm{2}}} \mathrm{sin}\theta\:\mathrm{cos}\theta\left(\mathrm{a}^{\mathrm{2}} \mathrm{sin}^{\mathrm{2}} \theta+\mathrm{b}^{\mathrm{2}} \mathrm{cos}^{\mathrm{2}} \theta\right)^{\frac{\mathrm{1}}{\mathrm{2}}} \mathrm{d}\theta \\ $$

Question Number 17203 Answers: 0 Comments: 3

∫_0 ^( 1) cot^(−1) (1−x+x^2 )dx

$$\int_{\mathrm{0}} ^{\:\mathrm{1}} \mathrm{cot}^{−\mathrm{1}} \left(\mathrm{1}−\mathrm{x}+\mathrm{x}^{\mathrm{2}} \right)\mathrm{dx} \\ $$

Question Number 17281 Answers: 0 Comments: 0

Question Number 17187 Answers: 3 Comments: 0

Question Number 17180 Answers: 0 Comments: 1

Question Number 17179 Answers: 1 Comments: 0

Question Number 17177 Answers: 1 Comments: 0

Question Number 17167 Answers: 1 Comments: 0

∫x^2 sin^(−1) 3x dx

$$\int\mathrm{x}^{\mathrm{2}} \mathrm{sin}^{−\mathrm{1}} \mathrm{3x}\:\mathrm{dx} \\ $$

Question Number 17158 Answers: 0 Comments: 4

Please solve Q. 16069. Ask from me the solution if needed and please explain it.

$$\mathrm{Please}\:\mathrm{solve}\:\mathrm{Q}.\:\mathrm{16069}.\:\mathrm{Ask}\:\mathrm{from}\:\mathrm{me}\:\mathrm{the} \\ $$$$\mathrm{solution}\:\mathrm{if}\:\mathrm{needed}\:\mathrm{and}\:\mathrm{please}\:\mathrm{explain}\:\mathrm{it}. \\ $$

Question Number 17153 Answers: 1 Comments: 0

If m, n ∈ N(n > m), then number of solutions of the equation n∣sin x∣ = m∣sin x∣ in [0, 2π] is

$$\mathrm{If}\:{m},\:{n}\:\in\:{N}\left({n}\:>\:{m}\right),\:\mathrm{then}\:\mathrm{number}\:\mathrm{of} \\ $$$$\mathrm{solutions}\:\mathrm{of}\:\mathrm{the}\:\mathrm{equation} \\ $$$${n}\mid\mathrm{sin}\:{x}\mid\:=\:{m}\mid\mathrm{sin}\:{x}\mid\:\mathrm{in}\:\left[\mathrm{0},\:\mathrm{2}\pi\right]\:\mathrm{is} \\ $$

Question Number 17152 Answers: 1 Comments: 0

If sinA = sinB and cosA = cosB, then (1) A = B + nπ, n ∈ I (2) A = B − nπ, n ∈ I (3) A = 2nπ + B, n ∈ I (4) A = nπ − B, n ∈ I

$$\mathrm{If}\:\mathrm{sin}{A}\:=\:\mathrm{sin}{B}\:\mathrm{and}\:\mathrm{cos}{A}\:=\:\mathrm{cos}{B},\:\mathrm{then} \\ $$$$\left(\mathrm{1}\right)\:{A}\:=\:{B}\:+\:{n}\pi,\:{n}\:\in\:{I} \\ $$$$\left(\mathrm{2}\right)\:{A}\:=\:{B}\:−\:{n}\pi,\:{n}\:\in\:{I} \\ $$$$\left(\mathrm{3}\right)\:{A}\:=\:\mathrm{2}{n}\pi\:+\:{B},\:{n}\:\in\:{I} \\ $$$$\left(\mathrm{4}\right)\:{A}\:=\:{n}\pi\:−\:{B},\:{n}\:\in\:{I} \\ $$

Question Number 17151 Answers: 1 Comments: 0

The solution of the equation cos^2 θ − 2cosθ = 4sinθ − sin2θ where θ ∈ [0, π] is

$$\mathrm{The}\:\mathrm{solution}\:\mathrm{of}\:\mathrm{the}\:\mathrm{equation} \\ $$$$\mathrm{cos}^{\mathrm{2}} \theta\:−\:\mathrm{2cos}\theta\:=\:\mathrm{4sin}\theta\:−\:\mathrm{sin2}\theta\:\mathrm{where} \\ $$$$\theta\:\in\:\left[\mathrm{0},\:\pi\right]\:\mathrm{is} \\ $$

Question Number 17150 Answers: 0 Comments: 3

If the equation cos x + 3 cos (2Kx) = 4 has exactly one solution, then (1) K is a rational number of the form (P/(P + 1)), P ≠ −1 (2) K is irrational number whose rational approximation does not exceed 2 (3) K is irrational number (4) K is a rational number of the form (P/(P − 1)), P ≠ 1

$$\mathrm{If}\:\mathrm{the}\:\mathrm{equation}\:\mathrm{cos}\:{x}\:+\:\mathrm{3}\:\mathrm{cos}\:\left(\mathrm{2}{Kx}\right)\:=\:\mathrm{4} \\ $$$$\mathrm{has}\:\mathrm{exactly}\:\mathrm{one}\:\mathrm{solution},\:\mathrm{then} \\ $$$$\left(\mathrm{1}\right)\:{K}\:\mathrm{is}\:\mathrm{a}\:\mathrm{rational}\:\mathrm{number}\:\mathrm{of}\:\mathrm{the}\:\mathrm{form} \\ $$$$\frac{{P}}{{P}\:+\:\mathrm{1}},\:{P}\:\neq\:−\mathrm{1} \\ $$$$\left(\mathrm{2}\right)\:{K}\:\mathrm{is}\:\mathrm{irrational}\:\mathrm{number}\:\mathrm{whose} \\ $$$$\mathrm{rational}\:\mathrm{approximation}\:\mathrm{does}\:\mathrm{not} \\ $$$$\mathrm{exceed}\:\mathrm{2} \\ $$$$\left(\mathrm{3}\right)\:{K}\:\mathrm{is}\:\mathrm{irrational}\:\mathrm{number} \\ $$$$\left(\mathrm{4}\right)\:{K}\:\mathrm{is}\:\mathrm{a}\:\mathrm{rational}\:\mathrm{number}\:\mathrm{of}\:\mathrm{the}\:\mathrm{form} \\ $$$$\frac{{P}}{{P}\:−\:\mathrm{1}},\:{P}\:\neq\:\mathrm{1} \\ $$

Question Number 17137 Answers: 0 Comments: 0

Solve the differential equation 2x[ye^x − 1]dx + e^y dy = 0

$$\mathrm{Solve}\:\mathrm{the}\:\mathrm{differential}\:\mathrm{equation}\: \\ $$$$\mathrm{2x}\left[\mathrm{ye}^{\mathrm{x}} \:−\:\mathrm{1}\right]\mathrm{dx}\:+\:\mathrm{e}^{\mathrm{y}} \:\mathrm{dy}\:=\:\mathrm{0} \\ $$

Question Number 17129 Answers: 1 Comments: 0

Question Number 17142 Answers: 0 Comments: 2

Find two primes a and b such that a−b=995

$$\mathrm{Find}\:\mathrm{two}\:\mathrm{primes}\:{a}\:\mathrm{and}\:{b}\:\mathrm{such} \\ $$$$\mathrm{that}\:\:\:\:\: \\ $$$$\:\:\:\:\:\:\:\:{a}−{b}=\mathrm{995} \\ $$

Question Number 17119 Answers: 0 Comments: 2

Question Number 17117 Answers: 1 Comments: 0

A clock has a pendulum made of iron rod of length 2.5m, if the clock keeps accurate time at 0°C. By how much time will it be late running at a temperature 30°C for 1 day. coefficient of linear expansivity of iron is 1.2 × 10^(−5) per k.

$$\mathrm{A}\:\mathrm{clock}\:\mathrm{has}\:\mathrm{a}\:\mathrm{pendulum}\:\mathrm{made}\:\mathrm{of}\:\mathrm{iron}\:\mathrm{rod}\:\mathrm{of}\:\mathrm{length}\:\mathrm{2}.\mathrm{5m}, \\ $$$$\mathrm{if}\:\mathrm{the}\:\mathrm{clock}\:\mathrm{keeps}\:\mathrm{accurate}\:\mathrm{time}\:\mathrm{at}\:\mathrm{0}°\mathrm{C}.\:\mathrm{By}\:\mathrm{how}\:\mathrm{much}\:\mathrm{time}\:\mathrm{will}\:\mathrm{it}\:\mathrm{be}\:\mathrm{late} \\ $$$$\mathrm{running}\:\mathrm{at}\:\mathrm{a}\:\mathrm{temperature}\:\mathrm{30}°\mathrm{C}\:\mathrm{for}\:\mathrm{1}\:\mathrm{day}.\:\mathrm{coefficient}\:\mathrm{of}\:\mathrm{linear}\:\mathrm{expansivity}\:\mathrm{of} \\ $$$$\mathrm{iron}\:\mathrm{is}\:\:\mathrm{1}.\mathrm{2}\:×\:\mathrm{10}^{−\mathrm{5}} \mathrm{per}\:\mathrm{k}. \\ $$

Question Number 17148 Answers: 1 Comments: 0

The number of solutions of the equation cos (π(√(x − 4))) cos (π(√x)) = 1 is

$$\mathrm{The}\:\mathrm{number}\:\mathrm{of}\:\mathrm{solutions}\:\mathrm{of}\:\mathrm{the}\:\mathrm{equation} \\ $$$$\mathrm{cos}\:\left(\pi\sqrt{{x}\:−\:\mathrm{4}}\right)\:\mathrm{cos}\:\left(\pi\sqrt{{x}}\right)\:=\:\mathrm{1}\:\mathrm{is} \\ $$

Question Number 17102 Answers: 0 Comments: 3

compute: Σ_(k = 0) ^∞ ((2k + 1)/2^(2(k + 1)) )

$$\mathrm{compute}:\:\:\:\underset{\mathrm{k}\:=\:\mathrm{0}} {\overset{\infty} {\sum}}\:\frac{\mathrm{2k}\:+\:\mathrm{1}}{\mathrm{2}^{\mathrm{2}\left(\mathrm{k}\:+\:\mathrm{1}\right)} } \\ $$

Question Number 17100 Answers: 1 Comments: 0

sec xcos 5x+1=0 find number of solution

$$\mathrm{sec}\:{x}\mathrm{cos}\:\mathrm{5}{x}+\mathrm{1}=\mathrm{0} \\ $$$${find}\:{number}\:{of}\:{solution} \\ $$

Question Number 17086 Answers: 1 Comments: 6

∫_(−1) ^2 (1/x^2 ) dx